Manufacturing method of electron tube

ABSTRACT

A first member made of an insulating material and a jig with a protrusion narrowing toward a distal end side are prepared, and at least one of the first member and the jig is heated to a temperature at which the first member can melt and deform. After the jig is brought into contact with the first member with the first member and the plurality of protrusions facing each other, the jig is removed, and an intermediate body is formed including the first member formed with a plurality of recesses, and a plurality of conductive members passing through the first member and projecting into the recesses. A second member is prepared, openings of the plurality of recesses are closed, and the second member is hermetically joined to the intermediate body to form a plurality of internal spaces where electron is emitted, and forming a joined body.

TECHNICAL FIELD

One aspect of the present invention relates to a manufacturing method ofan electron tube.

BACKGROUND

As a conventional technique related to a manufacturing method of anelectron tube, for example, there are known the techniques described inJapanese Unexamined Patent Publication No. 2013-19719, U.S. Pat. No.5,500,531, and Japanese Patent No. 3470077. Japanese Unexamined PatentPublication No. 2013-19719 describes a flame sensor including a lowerlid provided with a cavity by etching, an upper lid joined to the lowerlid so as to close the cavity, and an electrode disposed in the cavity.U.S. Pat. No. 5,500,531 describes a discharge type sensor for detectingultra-violet rays, including a silicon substrate having a cavity formedby etching, a glass substrate provided on the silicon substrate, and anelectrode provided in the cavity.

Japanese Patent No. 3470077 describes a discharge light-emitting deviceincluding a substrate and a transparent substrate that are stacked oneach other, and an internal electrode and an external electrode that isformed on the substrate and the transparent substrate. In the dischargelight-emitting device described in Japanese Patent No. 3470077, adischarging space is formed between the substrate and the transparentsubstrate.

SUMMARY

In recent years, as a manufacturing method of an electron tube asdescribed above, for example, a method capable of easily manufacturingan internal structure of the electron tube is required while applicationof the electron tube to various fields has expanded.

One aspect of the present invention is to provide a manufacturing methodof an electron tube that can easily manufacture an internal structure ofthe electron tube.

The manufacturing method of an electron tube according to the presentinvention includes: a first step of preparing a first member made of aninsulating material and a jig provided with a juxtaposed protrusionnarrowing toward a distal end side and removably holding a conductivemember, and heating at least one of the first member and the jig to atemperature at which the first member can melt and deform; after thefirst step, a second step of bringing the jig into contact with thefirst member to allow the plurality of protrusions to be embedded in thefirst member in a state where the first member and the plurality ofprotrusions are facing each other, removing the jig, and forming anintermediate body that includes the first member in which a plurality ofrecesses expanding toward an opening side are formed corresponding tothe plurality of protrusions, and includes a plurality of the conductivemembers passing through the first member and projecting into therecesses; and after the second step, a third step of preparing a secondmember, hermetically joining the second member to the intermediate bodyby closing openings of the plurality of recesses to form a plurality ofinternal spaces where electron is emitted, and forming a joined body.

In this manufacturing method of an electron tube, it is possible tocollectively mold, with use of a jig, a plurality of recesses in which aconductive member passing through the first member projects, andcollectively manufacture an internal structure having an internal spaceformed by the recess. That is, the internal structure of the electrontube can be easily manufactured.

A manufacturing method of an electron tube according to one aspect ofthe present invention may further include, after the third step, afourth step of cutting the joined body into a plurality of electrontubes so as to have at least one internal space. In this case, it ispossible to stably manufacture a plurality of electron tubes having apredetermined internal structure.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, a side surface of a protrusion of the jig may becontinuously inclined such that the protrusion narrows toward the distalend side. In this case, it is possible to release the jig whilesuppressing breakage of the first member and the jig, and to stablymanufacture the internal structure of the electron tube.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, the protrusion of the jig may have a holdingrecess that holds, in a state where one end side of the conductivemember projects from the protrusion, another end side of the conductivemember, and a gap may be formed at least in a part between another endside of the conductive member held in the holding recess and a sidesurface of the holding recess. In this case, since the conductive membercan be covered by filling the first member in the gap, it is possible tostably fix the conductive member even when the conductive member isprojected.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, another end side of the conductive member held inthe holding recess may have an enlarged part expanding toward theanother end side, and a gap may be formed at least in a part between theenlarged part and a side surface of the holding recess. In this case,since the enlarged part can be covered by filling the first member inthe gap, a contact area between the conductive member and the firstmember can be enlarged. Therefore, even when the conductive member isprojected, it is possible to stably fix the conductive member.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, a side surface of the enlarged part may becontinuously inclined such that the conductive member expands towardanother end side of the conductive member. In this case, it is easy tocover the side surface of the enlarged part with the first memberwithout a gap.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, an area around the protrusion of the jig mayremovably hold the power supply member; in the second step, the jig maybe brought into contact with the first member such that the power supplymember is further embedded in the first member, to form an intermediatebody further including the power supply member; and in the third step, acounter electrode member may be provided on the second member so as toface the conductive member projecting into the recess, and the counterelectrode member may be electrically connected to the power supplymember. In this case, it becomes possible to form a power supply path tothe counter electrode member on the second member side without requiringa separate step.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, the second member may be made of an insulatingmaterial. In this case, it becomes possible to improve the withstandvoltage capability in the internal space of the manufactured electrontube.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, at least one of a recess, a protrusion, or arough surface part may be formed on at least a part of a surfaceconstituting the protrusion of the jig. In this case, at least one of arecess, a protrusion, or a rough surface part can be formed on a surfaceconstituting the internal space, and a creeping distance in the internalspace can be lengthened.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, after the first step, there may be furtherprovided a step of pressing, with a pressing member, a side opposite toa side to be in contact with the jig in the first member, and at leastone of a recess, a protrusion, or a rough surface part may be formed ina contact region of the pressing member with the first member. In thiscase, at least one of a recess, a protrusion, or a rough surface partcan be formed on an outer surface of the first member, and a creepagedistance on an outer surface of the electron tube can be lengthened.

In a manufacturing method of an electron tube according to one aspect ofthe present invention, in the second step, the conductive member may beembedded in the first member while exposing one end of the conductivemember from the first member such that the conductive member passesthrough the first member in the intermediate body, or the first membermay be polished until one end of the conductive member is exposed fromthe first member. In this case, a configuration in which the conductivemember passes through the first member can be concretely realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an electron tube according to afirst embodiment;

FIG. 2 is an exploded perspective view of the electron tube of FIG. 1;

FIG. 3 is a plan view of a jig used in a manufacturing method of theelectron tube of FIG. 1;

FIG. 4A is a partial cross-sectional view illustrating the manufacturingmethod of the electron tube of FIG. 1;

FIG. 4B is a partial cross-sectional view showing a continuation of FIG.4A;

FIG. 5A is a partial cross-sectional view showing a continuation of FIG.4B;

FIG. 5B is a partial cross-sectional view showing a continuation of FIG.5A;

FIG. 6A is a partial cross-sectional view showing a continuation of FIG.5B;

FIG. 6B is a partial cross-sectional view showing a continuation of FIG.6A;

FIG. 6C is a partial cross-sectional view showing a continuation of FIG.6B;

FIG. 7A is a partial cross-sectional view showing a continuation of FIG.6C;

FIG. 7B is a partial cross-sectional view showing a continuation of FIG.7A;

FIG. 7C is a partial cross-sectional view showing a continuation of FIG.7B;

FIG. 8A is a partial cross-sectional view showing a continuation of FIG.7C;

FIG. 8B is a partial cross-sectional view showing a continuation of FIG.8A;

FIG. 9 is a partial cross-sectional view illustrating a manufacturingmethod of an electron tube according to a second embodiment;

FIG. 10A is a partial cross-sectional view illustrating a manufacturingmethod of an electron tube according to a third embodiment;

FIG. 10B is another partial cross-sectional view illustrating themanufacturing method of the electron tube according to the thirdembodiment;

FIG. 11A is a partial cross-sectional view illustrating a manufacturingmethod of an electron tube according to a fourth embodiment;

FIG. 11B is another partial cross-sectional view illustrating themanufacturing method of the electron tube according to the fourthembodiment;

FIG. 12A is a partial cross-sectional view illustrating a manufacturingmethod of an electron tube according to a fifth embodiment;

FIG. 12B is another partial cross-sectional view illustrating themanufacturing method of the electron tube according to the fifthembodiment;

FIG. 13A is a partial cross-sectional view illustrating a manufacturingmethod of an electron tube according to a modification of the fifthembodiment;

FIG. 13B is another partial cross-sectional view illustrating themanufacturing method of the electron tube according to the modificationof the fifth embodiment;

FIG. 14A is a cross-sectional view of an electron tube according to afirst modification;

FIG. 14B is a cross-sectional view of an electron tube according to asecond modification;

FIG. 15A is a cross-sectional view of an electron tube according to athird modification;

FIG. 15B is a cross-sectional view of an electron tube according to afourth modification; and

FIG. 15C is a cross-sectional view of an electron tube according to afifth modification.

DETAILED DESCRIPTION

Hereinafter, one embodiment will be described in detail with referenceto the drawings. In the following description, the same referencenumerals are used for the same or corresponding elements, and redundantexplanations are omitted. Further, dimensions in the followingdescription do not necessarily correspond to the drawings.

First Embodiment

As shown in FIGS. 1 and 2, an electron tube 1 is a discharge tubeserving as a light receiving element (energy detecting element) in whicha discharge gas such as neon or hydrogen is enclosed. The electron tube1 is used as an ultraviolet detector (flame sensor) that detectsultraviolet rays with use of photoelectron emission effect and dischargephenomenon. The electron tube 1 includes a housing 2 having an internalspace R airtightly sealed, and a cathode K and an anode A as electrodesfor reception of light in the internal space R. The electron tube 1 hasan outer shape of a rectangular parallelepiped and has dimensions of 10mm×10 mm×5 mm, for example.

The housing 2 has a main body part 5 and a lid part 6. The housing 2 hasa structure in which the main body part 5 and the lid part 6 arehermetically joined by a sealing part S, and a discharge gas is enclosedin the internal space R. The main body part 5 is made of an insulatingmaterial and is formed of, for example, quartz, glass, ceramics, or thelike. The main body part 5 includes a first plate-shaped part 7 and aside wall part 8 provided on the first plate-shaped part 7. The firstplate-shaped part 7 has a rectangular flat plate shape. A thickness ofthe first plate-shaped part 7 is, for example, 1 mm. The side wall part8 is erected on an edge of the first plate-shaped part 7 and has arectangular frame shape. In the main body part 5, a recess 9constituting the internal space R is formed by a region surrounded bythe side wall part 8. In the internal space R, electron emission isperformed.

The recess 9 expands from a bottom surface 9 a thereof (an inner surfaceof the first plate-shaped part 7) toward an opening 9 b side. The recess9 is space having a truncated square shape. A depth of the recess 9 is,for example, 2.5 mm. The opening 9 b of the recess 9 has, for example, arectangular shape of 7 mm×7 mm. Four side surfaces 9 c of the recess 9are inclined continuously (so as to form a smooth surface) such that therecess 9 expands toward the opening 9 b side. An inclination angle θ1 ofthe side surface 9 c when a direction orthogonal to the bottom surface 9a is set to a reference(0°) may be 3° to 10°, or may be 5°. In otherwords, when the electron tube 1 is viewed in a cross section along anerecting direction of the side wall part 8 (when seeing FIG. 1 from adirection perpendicular to the page), an angle θ2 formed by the bottomsurface 9 a and the side surface 9 c may be 93° to 100°, or may be 95°.

The lid part 6 is airtightly joined to the main body part 5 by thesealing part S so as to close the opening 9 b of the recess 9. Theinternal space R is defined by an inner surface of the lid part 6, thesealing part S, and the bottom surface 9 a and the side surface 9 c ofthe recess 9. The lid part 6 is made of an insulating material havinglight transmittance (ultraviolet ray transmittance, energytransmittance), and is formed of, for example, quartz, ultraviolettransmissive glass, or the like. The lid part 6 includes a secondplate-shaped part 10 (here, the lid part 6 is the second plate-shapedpart 10). The second plate-shaped part 10 has a rectangular flat plateshape. A thickness of the second plate-shaped part 10 is, for example, 1mm. The second plate-shaped part 10 is fixed on the side wall part 8 andfaces the first plate-shaped part 7. Between the second plate-shapedpart 10 and the side wall part 8, a first base film 15, a sealingmaterial 16, and a second base film 17 constituting the sealing part Sare interposed in this order from the side wall part 8 to the secondplate-shaped part 10. Note that FIG. 2 is illustrated with the firstbase film 15 and the second base film 17 omitted.

The first base film 15 is a film to improve adhesiveness between thesealing material 16 and the side wall part 8. The second base film 17 isa film to improve adhesiveness between the sealing material 16 and thesecond plate-shaped part 10. As the first base film 15 and the secondbase film 17, chromium (Cr)/nickel (Ni), titanium (Ti)/platinum(Pt)/gold (Au), or the like can be used. The sealing material 16 is amember to hermetically seal between the side wall part 8 and the secondplate-shaped part 10. As the sealing material 16, indium (In), a brazingfiller metal such as gold tin (AuSn), frit glass, or the like can beused. The first base film 15, the sealing material 16, and the secondbase film 17 have a rectangular frame shape provided on a periphery ofthe recess 9 when viewed from the opening 9 b side of the recess 9.

The cathode (electrode) K includes a photoelectron emitting part 14described later. The photoelectron emitting part 14 is held at a distalend of a penetrating member 3, to be disposed at a desired position inthe internal space R and electrically connected to the penetratingmember 3. The photoelectron emitting part 14 serves as a photoelectronemitting electrode when a desired potential is applied through thepenetrating member 3.

The penetrating member 3 is a conductive member passing through thefirst plate-shaped part 7 of the main body part 5. The penetratingmember 3 is made of, for example, Kovar metal. The penetrating member 3has, on a base end side thereof, a columnar part 3 a extendingsubstantially in a cylindrical shape with a substantially constantdiameter. The penetrating member 3 has, on a distal end side thereof, alarge-diameter part 3 b having a diameter larger than that of thecolumnar part 3 a. A base end side of the large-diameter part 3 b has anenlarged part 3 b ₁ enlarged in diameter (expanding) toward a distal endside. The distal end side from the enlarged part 3 b ₁ is a cylindricalholding part 3 b ₂ that holds, on a distal end face thereof, thephotoelectron emitting part 14. Further, a length of the columnar part 3a is larger than a thickness of the first plate-shaped part 7.

The penetrating member 3 is exposed in an external space (a spaceoutside the electron tube 1) at a base end side (base end face) of thecolumnar part 3 a so as to be flush with an outer surface of the firstplate-shaped part 7, and fixed to the first plate-shaped part 7 suchthat the large-diameter part 3 b and a part of the distal end side ofthe columnar part 3 a project into the internal space R from the bottomsurface 9 a of the recess 9 toward the lid part 6 side. That is, thepenetrating member 3 has an internal space projecting part 11 projectinginto the internal space R from a central part of the bottom surface 9 aof the recess 9, and the internal space projecting part 11 is formed bythe large-diameter part 3 b and a part of the distal end side of thecolumnar part 3 a. Further, the internal space projecting part 11 hasthe enlarged part 3 b ₁ enlarged in diameter (expanding) toward thedistal end side, and the enlarged part 3 b ₁ is formed by a part of thebase end side of the large-diameter part 3 b.

A side surface of the enlarged part 3 b ₁ is inclined continuously (soas to form a smooth surface) such that the penetrating member 3 expandstoward the distal end side. The enlarged part 3 b ₁ has a truncated coneshape. A distal end side of the internal space projecting part 11 fromthe enlarged part 3 b ₁ is the holding part 3 b ₂. The holding part 3 b₂ is formed by a part of the distal end side of the large-diameter part3 b. The holding part 3 b ₂ has a diameter equal to or larger than thatof the enlarged part 3 b ₁, and the enlarged part 3 b ₁ has a largerdiameter than that of on the base end side (the diameter of the columnarpart 3 a) from the enlarged part 3 b ₁. That is, in the internal spaceprojecting part 11, the diameter of the holding part 3 b ₂, which is thedistal end side from the enlarged part 3 b ₁, is larger than thediameter on the base end side (the diameter of the columnar part 3 a)from the enlarged part 3 b ₁. For example, the diameter of the holdingpart 3 b ₂ of the penetrating member 3 is φ2 mm, the diameter of thebase end side (the diameter of the columnar part 3 a) from the enlargedpart 3 b ₁ is φ1 mm, and a total length of the penetrating member 3 is 3mm. Such a penetrating member 3 has a mushroom shape, and it can also besaid that the enlarged part 3 b ₁ and the holding part 3 b ₂, which area cap portion of the mushroom shape, mainly project into the internalspace R.

On a distal end face of the holding part 3 b ₂, the disc-shapedphotoelectron emitting part 14 serving as a photoelectron emissionelectrode is joined coaxially with the penetrating member 3. Unlike thepenetrating member 3, in the photoelectron emitting part 14, it is notnecessary to consider adhesiveness with the main body part 5 and thelike. Therefore, as a material of the photoelectron emitting part 14, amaterial focusing on a photoelectric conversion efficiency can beselected. For example, the photoelectron emitting part 14 is made of Ni(nickel). The photoelectron emitting part 14 has a dimension of φ4 mmand a thickness of 0.3 mm, for example.

A periphery of the enlarged part 3 b ₁ and a portion on the base endside from the enlarged part 3 b ₁ (a part of the distal end side of thecolumnar part 3 a) in the internal space projecting part 11 are coveredwith an insulating part 12. In other words, sides of the internal spaceprojecting part 11 other than the holding part 3 b ₂ are surrounded bythe insulating part 12. The insulating part 12 is made of an insulatingmaterial, and is formed of, for example, quartz, glass, ceramics, or thelike. The insulating part 12 of the present embodiment is formedintegrally with the first plate-shaped part 7 of the main body part 5.An outer peripheral surface of the insulating part 12 forms a sidesurface of a truncated cone, and is inclined continuously (so as to forma smooth surface) so as to decrease in diameter from the bottom surface9 a of the recess 9 toward the opening 9 b side.

The anode (another electrode) A includes a counter electrode (counterelectrode member) 4. The counter electrode 4 is provided on the lid part6 so as to face the penetrating member 3 and the photoelectron emittingpart 14. The counter electrode 4 is, for example, a mesh-shapedelectrode provided with an opening through which light transmittedthrough the lid part 6 can pass. The counter electrode 4 faces thephotoelectron emitting part 14 on the penetrating member 3 with adistance of a predetermined length. The predetermined length is, forexample, a length obtained by adding, to 0.2 mm, respective thicknessesof the first base film 15, the sealing material 16, and the second basefilm 17. The counter electrode 4 is formed on the inner surface of thelid part 6 by vapor deposition. The counter electrode 4 is a metal filmsuch as aluminum (Al) or Cr. The counter electrode 4 is electricallyconnected to a power supply part 13.

The power supply part 13 is a member to supply power to the counterelectrode 4. The power supply part 13 is made of a conductive material.The power supply part 13 passes through the main body part 5 withoutbeing exposed in the internal space R. Specifically, the power supplypart 13 has a substantially cylindrical shape having a substantiallyconstant diameter and extending with a depth direction of the recess 9as an axial direction. The power supply part 13 is buried inside thefirst plate-shaped part 7 and the side wall part 8, and passes throughwithout being exposed in the internal space R. The power supply part 13is provided on the periphery of the recess 9 in the main body part 5.The power supply part 13 is formed of, for example, Kovar metal. Adistal end (distal end face) on the opening 9 b side of the power supplypart 13 is exposed at an end face on the lid part 6 side of the sidewall part 8 so as to be flush with the end face, and is electricallyconnected to the counter electrode 4 via the first base film 15, thesealing material 16, and the second base film 17. Whereas, a base end(base end face) on the first plate-shaped part 7 side of the powersupply part 13 is exposed so as to be flush with the outer surface ofthe first plate-shaped part 7 in the outer space (space outside theelectron tube 1).

An operation principle of the electron tube 1 configured as describedabove will be described. Here, a description will be given to an aspectin which, in a use state of the electron tube 1, a negative voltage isapplied to the cathode K (photoelectron emitting part 14) by supplying anegative voltage to the penetrating member 3, and a signal is taken outfrom the anode A (counter electrode 4) having a ground potential byconnecting the power supply part 13 to the ground potential. Asdescribed above, in a state where a voltage is applied between thecathode K (photoelectron emitting part 14) and the anode A (counterelectrode 4), when ultraviolet rays are incident on the cathode K(photoelectron emitting part 14) through an opening of the lid part 6and the counter electrode 4, photoelectrons are emitted from the cathodeK (photoelectron emitting part 14) (photoelectron emission effect). Whenthe photoelectrons are attracted to the anode A (counter electrode 4) byan electric field formed by the voltage applied between the cathode K(photoelectron emitting part 14) and the anode A (counter electrode 4),the photoelectrons collide with discharge gas molecules in the internalspace R to ionize the discharge gas molecules. Among electrons andpositive ions generated by ionization, electrons further repeatcollision and ionization with other discharge gas molecules to generatesecondary electrons and reach the anode A (counter electrode 4).Whereas, positive ions are accelerated toward the cathode K(photoelectron emitting part 14), and when the positive ions areincident on the cathode K (photoelectron emitting part 14), electronsare emitted from the cathode K (photoelectron emitting part 14). Then,when the electrons are attracted to the anode A (counter electrode 4),the electrons collide with the discharge gas molecules in the internalspace R to ionize the discharge gas molecules. Repetition of suchelectron multiplication causes space discharge, and causes a largecurrent to abruptly flow between the cathode K (photoelectron emittingpart 14) and the anode A (counter electrode 4). By detecting the currentwith the anode A (counter electrode 4), ultraviolet rays can bedetected. Thus, in the electron tube 1, ultraviolet rays are detectedwith use of the photoelectric emission effect and the dischargephenomenon.

Next, a manufacturing method for manufacturing the electron tube 1 willbe described with reference to FIGS. 3 to 8B. FIGS. 4 to 8B illustratemerely a part of a cross section corresponding to the cross sectiontaken along the line A-A of FIG. 3 (merely a region corresponding to oneelectron tube 1), and, as shown in FIG. 3, for example, 25 pieces offive rows and five columns of the electron tube 1 are actuallymanufactured collectively. Further, in the description of themanufacturing method, the base end of the penetrating member (conductivemember) 3 and the power supply part 13 is defined as one end, and thedistal end is defined as another end.

First, as shown in FIGS. 3 and 4A, a jig 20 is prepared. The jig 20 is amold to shape the main body part 5. The jig 20 includes a flat platepart 21, a protrusion 22 arranged in a matrix shape on a surface 21 a ofthe flat plate part 21, and a hole 23 formed around each protrusion 22in the flat plate part 21.

The protrusion 22 has a shape corresponding to the recess 9. Theprotrusion 22 has a truncated square shape narrowing toward a topsurface 22 t of a distal end. A side surface 22 s of the protrusion 22is inclined continuously (so as to form a smooth surface) such that theprotrusion 22 narrows toward the distal end side. The top surface 22 tcorresponds to the bottom surface 9 a of the recess 9, and the sidesurface 22 s corresponds to the side surface 9 c of the recess 9. Aninclination angle θ1m of the side surface 22 s of the protrusion 22 whena direction orthogonal to the surface 21 a is set to the reference (0°)may be 3° to 10°, or may be or 5°. In other words, when the jig 20 isviewed in a cross section along an erecting direction of the protrusion22 (when seeing FIG. 4A from a direction perpendicular to the page), anangle θ2m formed by the surface 21 a and the side surface 22 s may be93° to 100°, or may be 95°. The protrusion 22 has a holding recess 22 athat holds the penetrating member 3 in a substantially central region onan upper surface.

In a state where one end side of the columnar part 3 a of thepenetrating member 3 projects from the protrusion 22, the holding recess22 a is inserted with and holds another end side of the columnar part 3a and the large-diameter part 3 b of the penetrating member 3. A depthof the holding recess 22 a is smaller than a projecting height of theprotrusion 22. A bottom surface 22 a ₁ side of the holding recess 22 ahas a cylindrical shape formed by the bottom surface 22 a ₁ and a sidesurface 22 a ₂, corresponding to the holding part 3 b ₂, which isanother end side of the large-diameter part 3 b. An opening side of theholding recess 22 a has a truncated cone shape enlarged in diametertoward the opening side, and is formed by a side surface 22 a ₃. Thatis, the side surface 22 a ₃ on the opening side of the holding recess 22a is inclined continuously (so as to form a smooth surface) such thatthe holding recess 22 a expands toward the opening side. The hole 23 isformed at a position close to each protrusion 22 on the surface 21 a ofthe flat plate part 21. A same number of the holes 23 as that of theprotrusions 22 are formed so as to be paired with the protrusions 22.The hole 23 holds an end of the power supply part (power supply member)13. The hole 23 has a cylindrical shape corresponding to the powersupply part 13.

In a state where the jig 20 is placed on a placing table (not shown), asshown in FIG. 4B, the penetrating member 3 is coaxially inserted intothe holding recess 22 a of the jig 20 with the holding part 3 b ₂, whichis another end side of the penetrating member 3, being a bottom side.That is, by supporting another end face of the holding part 3 b ₂ of thepenetrating member 3 with the bottom surface 22 a ₁ of the holdingrecess 22 a, the penetrating member 3 is arranged so as to erect in theholding recess 22 a at another end side. Further, since a side surfaceof the holding part 3 b ₂ is also supported by the side surface 22 a ₂of the holding recess 22 a, the penetrating member 3 is held more stablyin the holding recess 22 a. This allows the penetrating member 3 to beremovably held by the holding recess 22 a. Additionally, another endside of the power supply part 13 is coaxially inserted into the hole 23of the jig 20, and the power supply part 13 is arranged so as to erectin the hole 23 at another end side. This allows the power supply part 13to be removably held by the hole 23. At this time, one end faces of thepenetrating member 3 and the power supply part 13, that is, the endfaces on a side projecting from the jig 20 are positioned substantiallyat the same position in axial directions of the penetrating member 3 andthe power supply part 13. Between the penetrating member 3 and the sidesurface of the holding recess 22 a, a gap G is formed. The gap G is aspace present around the penetrating member 3 in the holding recess 22a. The gap G includes a gap G1 between the enlarged part 3 b ₁ and aninner surface of the holding recess 22 a. In practice, there is also aslight gap between the holding recess 22 a and the holding part 3 b ₂ inorder to removably hold the penetrating member 3 with the holding recess22 a, but this gap is not included in the gap G.

In addition to preparing such a jig 20, as shown in FIG. 5A, a firstmember 30 made of an insulating material such as glass is prepared. Thefirst member 30 has a flat plate shape and has dimensions of 80 mm×80mm×4 mm, for example. The size of the first member 30 includes a cuttingmargin in a cutting step to be described later.

In a state where the first member 30 is held by a holding member (notshown), the first member 30 is disposed at a position facing the jig 20holding the penetrating member 3 and the power supply part 13, and thefirst member 30 and a plurality of protrusions 22 are opposed to eachother. Then, at least one (here, both) of the jig 20 and the firstmember 30 is heated to a temperature at which the first member 30 canmelt and deform. For example, the jig 20 and the first member 30,including the placing table and the holding member, are disposed in atemperature atmosphere in which the first member 30 can melt and deform.Therefore, the jig 20, the placing table, and the holding member aremade of a material excellent in stability at high temperature withoutmelting and deformation even at a temperature at which the first member30 can melt and deform. In a case where the first member 30 is made ofglass, the temperature at which the first member 30 can melt and deformis, for example, a temperature equal to or higher than the glasstransition point.

Subsequently, as shown in FIG. 5B, in a state where the first member 30and the plurality of protrusions 22 are facing each other, the pluralityof protrusions 22, the penetrating member 3, and the power supply part13 are embedded in the first member 30, by bringing the jig 20 and thefirst member 30 close to and into contact with each other to presseither one of the jig 20 and the first member 30 against the other (oreach other). At that time, the first member 30 also flows into and fillsthe gap G including the gap G1 around the enlarged part 3 b ₁. Since thefirst member 30 hardly flows between the side surface of the holdingpart 3 b ₂ and the side surface 22 a ₂, the first member 30 does notflow at least in between another end face of the holding part 3 b ₂ andthe bottom surface 22 a ₁. That is, at least another end face of theholding part 3 b ₂ of the penetrating member 3 is not covered with theinsulating material. Therefore, it is possible to reliably secureelectrical connection with the photoelectron emitting part 14 at a timeof joining with the photoelectron emitting part 14 described later.Further, here, up to one end faces of the penetrating member 3 and thepower supply part 13 are embedded in the first member 30 so as to beburied (such that one end faces are not exposed from the first member30). Thereafter, as shown in FIG. 6A, the jig 20 is removed (released).In other words, the first member 30, the penetrating member 3, and thepower supply part 13 are taken out from the jig 20.

Subsequently, as shown in FIG. 6B, the first member 30, the penetratingmember 3, and the power supply part 13 are arranged upside down suchthat a direction of the opening 9 b of the recess 9 is changed by 180°.Note that this step of arranging upside down is a step for the sake ofconvenience of explanation, and may be omitted in an actualmanufacturing step.

Subsequently, as shown in FIG. 6C, a surface 30 a of the first member 30on a side opposite to the opening 9 b side of the recess 9 is polisheduntil one ends of the penetrating member 3 and the power supply part 13are exposed from the surface 30 a. Similarly, another end of the powersupply part 13 is polished so as to be flush with a surface 30 b on theopening 9 b side of the recess 9 in the first member 30. Thereby, anintermediate body N1 is foamed.

The intermediate body N1 includes: the first member 30 in which aplurality of recesses 9 expanding toward the opening 9 b side are formedcorresponding to the plurality of protrusions 22; a plurality ofpenetrating members 3 passing through the first member 30 and projectinginto the recesses 9; and a plurality of power supply parts 13 passingthrough the periphery of the recesses 9 of the first member 30. In thepresent embodiment, “a plurality of” corresponds to, for example, 25pieces of five rows and five columns as described above. The internalspace projecting part 11 is formed by a portion inserted into theholding recess 22 a in the penetrating member 3, that is, thelarge-diameter part 3 b (the enlarged part 3 b ₁ and the holding part 3b ₂) and a part of another end side of the columnar part 3 a. Theinsulating part 12 is formed by the first member 30 filled in the gap G(see FIG. 5A) including the gap G1 around the enlarged part 3 b ₁.

Subsequently, as shown in FIG. 7A, the photoelectron emitting part 14serving as the cathode K is arranged coaxially with the penetratingmember 3 and joined to a distal end face on the holding part 3 b ₂ sidein the penetrating member 3 in the recess 9. A method of joining thephotoelectron emitting part 14 and the penetrating member 3 is notparticularly limited, and the joining can be performed by laser welding,resistance welding, brazing material, or the like, for example.Subsequently, as shown in FIG. 7B, the first base film 15 is formed onthe periphery of each recess 9 on the surface 30 b of the first member30. Then, as shown in FIG. 7C, the sealing material 16 is laminated oneach of the first base films 15.

Subsequently, as shown in FIG. 8A, a second member 40 is prepared. Thesecond member 40 has a flat plate shape and has dimensions of 80 mm×80mm×1 mm, for example. The second member 40 has a surface 40 a of a sizecorresponding to the first member 30 in the intermediate body N1. On thesurface 40 a of the second member 40, the counter electrode (counterelectrode member) 4 is vapor-deposited at a plurality of positionscorresponding to individual penetrating members 3 (photoelectronemitting parts 14) and individual power supply parts 13 of theintermediate body N1. That is, when the second member 40 is air-tightlyjoined to the intermediate body N1 in a subsequent stage, the counterelectrode 4 is provided on the second member 40 so as to face eachpenetrating member 3 (photoelectron emitting part 14) and the each powersupply part 13. Then, the second base film 17 is formed at a positionfacing the sealing material 16.

Subsequently, as shown in FIG. 8B, in the gas atmosphere, the secondmember 40 is stacked and airtightly joined on the intermediate body N1such that the plurality of recesses 9 are hermetically sealed to form aplurality of internal spaces R enclosing gas in the surroundingatmosphere. At this time, each counter electrode 4 is opposed to eachpenetrating member 3 (photoelectron emitting part 14), and each counterelectrode is electrically connected to each power supply part 13.Thereby, a joined body N2 is formed.

Finally, the joined body N2 is cut for each of the plurality of internalspaces R. For example, an intended cutting line is set in a grid patternso as to pass between adjacent internal spaces R, and the joined body N2is cut along the intended cutting line. A cutting method in the cuttingstep is not particularly limited, and various known cutting methods canbe adopted. This causes the joined body N2 to be divided as a pluralityof electron tubes 1 in which the main body part 5 is formed by the firstmember 30 and the lid part 6 is formed by the second member 40. Thus,the manufacture of the electron tube 1 is completed.

As described above, in the manufacturing method of the electron tube 1,it is possible to collectively mold, with use of the jig 20, a pluralityof recesses 9 in which the penetrating members (conductive members) 3passing through the first member 30 project inside, and collectivelymanufacture internal structures having the internal spaces R formed bythe recesses 9. That is, the internal structure of the electron tube 1can be easily manufactured.

The manufacturing method of the electron tube 1 includes, after the stepof forming the joined body N, a step of cutting the joined body N2 intothe plurality of electron tubes 1 so as to include at least one internalspace R. This enables stable manufacturing of the plurality of electrontubes 1 having a predetermined internal structure.

In the manufacturing method of the electron tube 1, the side surface 22s of the protrusion 22 of the jig 20 is inclined continuously (so as toform a smooth surface) such that the protrusion 22 narrows toward thetop surface 22 t on the distal end side. In this case, it is possible torelease the jig 20 while suppressing breakage of the first member 30 andthe jig 20. The internal structure of the electron tube 1 can be stablymanufactured.

In the manufacturing method of the electron tube 1, in a state where oneend side of the penetrating member 3 projects from the protrusion 22,the protrusion 22 of the jig 20 has the holding recess 22 a to beinserted with and hold another end side of the penetrating member 3.Between another end side of the penetrating member 3 inserted into theholding recess 22 a and a side surface of the holding recess 22 a, thegap G is formed. In this case, since the penetrating member 3 can becovered by filling the first member 30 in the gap G, it becomes possibleto stably fix the penetrating member 3 even when the penetrating member3 is projected. Meanwhile, it suffices that the gap G is formed at leastin a part between the penetrating member 3 and the side surface of theholding recess 22 a.

In the manufacturing method of the electron tube 1, the gap G1 is formedbetween the enlarged part 3 b ₁ of the penetrating member 3 inserted andheld in the holding recess 22 a and the side surface of the holdingrecess 22 a. In this case, since the enlarged part 3 b ₁ can be coveredby filling the first member 30 in the gap G1, a contact area between thepenetrating member 3 and the first member 30 can be enlarged. It ispossible to stably fix the penetrating member 3 even when thepenetrating member 3 is projected. Meanwhile, it suffices that the gapG1 is formed at least in a part between the enlarged part 3 b ₁ and theside surface of the holding recess 22 a. Further, since the enlargedpart 3 b ₁ can suppress the insulating part 12 from reaching another endface of the holding part 3 b ₂, electrical connection with thephotoelectron emitting part 14 can be reliably secured.

In the manufacturing method of the electron tube 1, a side surface ofthe enlarged part 3 b ₁ may be continuously inclined such that thepenetrating member 3 expands toward another end side of the penetratingmember 3. In this case, it is easy to cover the side surface of theenlarged part 3 b ₁ with the first member 30 without a gap. It ispossible to further stably fix the penetrating member 3 even when thepenetrating member 3 is projected.

In the manufacturing method of the electron tube 1, an area around theprotrusion 22 of the jig 20 removably holds the power supply part 13.The jig 20 is brought into contact with the first member 30 such thatthe power supply part 13 is embedded in the first member 30, to form theintermediate body N1 including the power supply part 13. Then, thecounter electrode 4 (counter electrode member) is provided on the secondmember 40 so as to face the penetrating member 3, and the counterelectrode 4 is electrically connected to the power supply part 13. Inthis case, it becomes possible to form a power supply path to thecounter electrode 4 on the second member 40 side without requiring aseparate step.

In the manufacturing method of the electron tube 1, the second member 40is made of an insulating material. In this case, it becomes possible toimprove the withstand voltage capability in the internal space R of themanufactured electron tube 1.

In the manufacturing method of the electron tube 1, the first member 30is polished until one ends of the penetrating member 3 and the powersupply part 13 are exposed from the first member 30. In this case, it ispossible to realize a configuration in which the penetrating member 3and the power supply part 13 pass through the first member 30.

In the electron tube 1, the withstand voltage capability in the internalspace R can be enhanced since a contact area with the housing 2 in theinternal space R can be reduced as compared with a case of using, forexample, a conductive film or the like provided along an inner wallsurface of the housing, by using the penetrating member 3 having theinternal space projecting part 11 for electrical connection with thecathode K. Further, since the recess 9 expands toward the opening 9 bside, it is possible to easily release a mold in a case where the mainbody part 5 is molded using the jig 20 (mold). Therefore, according tothe electron tube 1, the withstand voltage capability can be improvedand manufacturing can be easily performed.

In the electron tube 1, the main body part 5 includes the firstplate-shaped part 7 and the frame-shaped side wall part 8 provided onthe first plate-shaped part 7. The lid part 6 includes the secondplate-shaped part 10 fixed on the side wall part 8 and facing the firstplate-shaped part 7. The penetrating member 3 passes through the firstplate-shaped part 7. According to this configuration, in the electrontube 1 including the housing 2 in which the first plate-shaped part 7and the second plate-shaped part 10 are facing each other, it ispossible to stably fix the penetrating member 3, so that a smallelectron tube 1 can be concretely and easily realized.

In the electron tube 1, the side surface 9 c of the recess 9 iscontinuously inclined such that the recess 9 expands toward the opening9 b side. According to this configuration, it is possible to stably formthe main body part 5 having the recess 9 of a fixed shape.

In the electron tube 1, a part of a side surface of the internal spaceprojecting part 11 of the penetrating member 3 is covered with theinsulating part 12 made of an insulating material. According to thisconfiguration, it is possible to reduce an exposure of the penetratingmember 3 in the internal space R, and improve the withstand voltagecapability in the internal space R.

In the electron tube 1, the cathode K (photoelectron emitting part 14)is held at the distal end side of the internal space projecting part 11of the penetrating member 3, and the internal space projecting part 11has the enlarged part 3 b ₁ expanding toward the distal end side.According to this configuration, it is possible to enlarge across-sectional area (to provide the holding part 3 b ₂) of the distalend side holding the cathode K (photoelectron emitting part 14) in theinternal space projecting part 11.

In the electron tube 1, the enlarged part 3 b ₁ is covered with theinsulating part 12. According to this configuration, it is possible toreduce an exposure of the enlarged part 3 b ₁ in the internal space R,and improve the withstand voltage capability in the internal space R. Onthe other hand, since the enlarged part 3 b ₁ can suppress theinsulating part 12 from reaching another end face of the holding part 3b ₂, electrical connection with the photoelectron emitting part 14 canbe reliably secured.

In the electron tube 1, a side surface of the enlarged part 3 b ₁ iscontinuously inclined such that the penetrating member 3 expands towardthe distal end side. According to this configuration, it is easy tocover the side surface of the enlarged part 3 b ₁ with the insulatingpart 12 without a gap, and it is easy to realize improvement of thewithstand voltage capability in the internal space R.

The electron tube 1 further includes the counter electrode 4 provided onthe lid part 6 so as to face the penetrating member 3, and the counterelectrode 4 is electrically connected to the power supply part 13passing through the main body part 5 without being exposed in theinternal space R. According to this configuration, it is possible toreduce an exposure, in the internal space R, of the power supply part 13electrically connected to the counter electrode 4, and improve thewithstand voltage capability in the internal space R.

In the electron tube 1, the lid part 6 is made of an insulating materialhaving light transmittance. According to this configuration, it ispossible to further improve the withstand voltage capability in theinternal space R, while configuring the lid part 6 as a window part forlight reception in the internal space R.

In the present embodiment, the steps shown in FIGS. 4A to 5A constitutea first step. The steps shown in FIGS. 5B to 7C constitute a secondstep. The steps shown in FIGS. 8A to 8B constitute a third step. A stepof cutting the joined body N2 for each of the plurality of internalspaces R constitutes a fourth step.

Second Embodiment

Next, a second embodiment will be described. In the description of thethird embodiment, points different from the first embodiment above willbe described, and similar description will be omitted.

As shown in FIG. 9, the second embodiment is different from the firstembodiment in that a first member 30X is used in place of the firstmember 30 (see FIG. 5A) in a manufacturing method of an electron tube.The first member 30X is similar to the first member 30 except that athrough hole 32 and a through hole 33 are provided at positions facing apenetrating member 3 and a power supply part 13. An inner diameter ofthe through hole 32 corresponds to an outer diameter of a columnar part3 a of the penetrating member 3, and an inner diameter of the throughhole 33 corresponds to an outer diameter of the power supply part 13.However, the inner diameter of the through holes 32 and 33 may beslightly larger than the outer diameters.

In the manufacturing method using the first member 30X, when the firstmember 30X and a jig 20 are arranged at positions facing each other, thethrough hole 32 is opposed to the penetrating member 3 and the throughhole 33 is opposed to the power supply part 13. Then, the plurality ofprotrusions 22, the penetrating member 3, and the power supply part 13are embedded in the first member 30X by bringing the jig 20 and thefirst member 30X close to and into contact with each other to presseither one of the jig 20 and the first member 30X against the other (oreach other). At that time, the penetrating member 3 is inserted into thethrough hole 32 and the power supply part 13 is inserted into thethrough hole 33.

As described above, the manufacturing method of the electron tubeaccording to the second embodiment also achieves effects similar tothose of the above-described embodiment. In addition, by using the firstmember 30X having the through hole 32 and the through hole 33, it ispossible to suppress the first member 30X from adhering to the one endfaces of the penetrating member 3 and the power supply part 13 exposedfrom the first member 30X, that is, a surface of an electricalconnection part when power is supplied to the penetrating member 3 andthe power supply part 13. In addition, since one end sides of thepenetrating member 3 and the power supply part 13 are smoothlyintroduced into the first member 30X, it is possible to suppress achange of the arrangement of the penetrating member 3 and the powersupply part 13 in embedding in the first member 30X.

Third Embodiment

Next, a third embodiment will be described. In the description of thethird embodiment, points different from the first embodiment above willbe described, and similar description will be omitted.

As shown in FIG. 10A, the third embodiment is different from the firstembodiment in that, in a manufacturing method of an electron tube, oneends of a penetrating member 3 and a power supply part 13 are exposedfrom a first member 30 such that the penetrating member 3 and the powersupply part 13 pass through the first member 30 in embedding thepenetrating member 3 and the power supply part 13 in the first member30. This causes, as shown in FIG. 10B, one ends of the penetratingmember 3 and the power supply part 13 to project from a surface 30 a ofthe first member 30 in an intermediate body N1 of the third embodiment.As a result, in the electron tube according to the third embodiment, oneends of the penetrating member 3 and the power supply part 13 projectoutward (atmosphere side) from a main body part 5.

As described above, the manufacturing method of the electron tubeaccording to the third embodiment also achieves effects similar to thoseof the above-described embodiment. Further, since one ends of thepenetrating member 3 and the power supply part 13 are exposed from thefirst member 30 such that the penetrating member 3 and the power supplypart 13 pass through the first member 30, it is possible to eliminatenecessity of polishing of the surface 30 a of the first member 30 afterembedding in the first member 30, enabling a manufacturing step to besimplified. Further, since one ends of the penetrating member 3 and thepower supply part 13 project, it is possible to facilitate electricalconnection, and in turn, power supply, to the penetrating member 3 andthe power supply part 13. In addition, using the first member 30X usedin the second embodiment as the first member 30 makes it possible tosuppress adhesion of the first member 30X to the surface of theelectrical connection part when power is supplied to the penetratingmember 3 and the power supply part 13.

Note that the present embodiment may include at least a part of thefeatures of other embodiments or modifications in place of or inaddition to the features of the first embodiment above.

Fourth Embodiment

Next, a fourth embodiment will be described. In the description of thefourth embodiment, points different from the first embodiment above willbe described, and similar description will be omitted.

As shown in FIG. 11A, the fourth embodiment is different from the firstembodiment in that a jig 20A is used in place of the jig 20 (see FIG.4B) in a manufacturing method of an electron tube. The jig 20A issimilar to the jig 20 except that a protrusion 25 and a recess 26 areformed on a distal end face of a protrusion 22.

As shown in FIG. 11B, in an intermediate body N1 according to themanufacturing method using the jig 20A, on a bottom surface 9 a of arecess 9, a protrusion 34 corresponding to the recess 26 is forming anda recess 35 corresponding to the protrusion 25 is formed. As a result,in the electron tube according to the fourth embodiment, the protrusion34 and the recess 35 are formed on the bottom surface 9 a of the recess9 constituting an internal space R.

As described above, the manufacturing method of the electron tubeaccording to the fourth embodiment also achieves effects similar tothose of the above-described embodiment. Further, by forming theprotrusion 34 and the recess 35 on the bottom surface 9 a of the recess9, it is possible to lengthen a creepage distance in the internal spaceR, specifically, a creepage distance between an anode A (counterelectrode 4), and a cathode K (photoelectron emitting part 14) and apenetrating member 3, and to further improve the withstand voltagecapability in the internal space R. Particularly, the recess 35 canincrease an enclosed volume of gas, making it possible to improve aservice life of the electron tube 1.

Note that, in the jig 20A, the protrusion 25 and the recess 26 areformed on the distal end face of the protrusion 22, but it suffices thatat least one of a recess, a protrusion, and a rough surface part isformed on at least a part of a surface constituting the protrusion 22.Similarly, in the electron tube according to the fourth embodiment, theprotrusion 34 and the recess 35 are formed on the bottom surface 9 a ofthe recess 9, but it suffices that at least one of a recess, aprotrusion, and a rough surface part is formed on at least a part of asurface constituting the internal space R. The rough surface part is arougher surface than a predetermined roughness, and is a surface onwhich fine unevenness is formed, such as satin, for example. The presentembodiment may include at least a part of the features of otherembodiments or modifications in place of or in addition to the featuresof the first embodiment above.

Fifth Embodiment

Next, a fifth embodiment will be described. In the description of thefifth embodiment, points different from the fourth embodiment above willbe described, and similar description will be omitted.

As shown in FIG. 12A, the fifth embodiment is different from the fourthembodiment in that, in a manufacturing method of an electron tube, aplurality of protrusions 61 and 62 are provided in a pressing member 60that presses a first member 30 in bringing a jig 20A and the firstmember 30 close to and into contact with each other to press either oneof the jig 20A and the first member 30 against the other (or eachother).

The plurality of protrusions 61 and 62 are formed in a contact region ofthe pressing member 60 with the first member 30. The protrusion 61 isprovided at a position facing a protrusion 25 of the jig 20A via thefirst member 30. The protrusion 62 is provided at a position facing arecess 26 of the jig 20A via the first member 30.

As shown in FIG. 12B, in an intermediate body N1 according to themanufacturing method using the pressing member 60, a recess 36 and arecess 37 are formed on a surface 30 a of the first member 30 on a sideopposite to an opening 9 b side of a recess 9. The recess 36 is formedby the protrusion 62. The recess 37 is formed by the protrusion 61. As aresult, in the electron tube according to the fifth embodiment, therecess 36 and the recess 37 are formed on an outer surface on a side(atmosphere side) opposite to the opening 9 b side of the recess 9 in amain body part 5.

As described above, the manufacturing method of the electron tubeaccording to the fifth embodiment also achieves effects similar to thoseof the above-described embodiment. Further, by forming the recess 36 andthe recess 37 on the surface of the main body part 5, it is possible tolengthen a creepage distance between an exposed part (base end face) ofa penetrating member 3 and the exposed part (base end face) of a powersupply part 13 on an outer surface of the electron tube 1, and improvethe withstand voltage capability.

Note that, in the pressing member 60, the protrusion 61 and theprotrusion 62 are formed in the contact region with the first member 30,but it suffices that at least one of a recess, a protrusion, and a roughsurface part is formed. Similarly, in the electron tube according to thefifth embodiment, the recess 36 and the recess 37 are formed on thesurface of the main body part 5, but it suffices that at least one of arecess, a protrusion, or a rough surface part is formed on at least apart of an outer surface of the main body part 5. In addition, the jig20 (see FIG. 4B) may be used in place of the jig 20A, and a protrusion34 and a recess 35 on a bottom surface 9 a of the recess 9 may beomitted.

The present embodiment may include at least a part of the features ofother embodiments or modifications in place of or in addition to thefeatures of the fourth embodiment above. For example, as shown in FIG.13A, in the manufacturing method according to the present embodiment,the first member 30X of the second embodiment may be used in place ofthe first member 30 (see FIG. 12A).

In addition, for example, in place of the pressing member 60 (see FIG.12A) formed with the protrusion 61 and the protrusion 62, a pressingmember 60A formed with a protrusion 62 and a recess 63 may be used. Inthis case, as shown in FIG. 13B, in the electron tube according to thepresent embodiment, on the surface of the main body part 5, on a side(atmosphere side) opposite to the opening 9 b side of the recess 9, arecess 36 is formed by the protrusion 62 and a protrusion 38 is formedby the recess 63.

Further, for example, in the manufacturing method according to thepresent embodiment, similarly to the third embodiment, the penetratingmember 3 and the power supply part 13 may be embedded with one ends ofthe penetrating member 3 and the power supply part 13 exposed from thefirst member 30 such that the penetrating member 3 and the power supplypart 13 pass through the first member 30, in embedding the penetratingmember 3 and the power supply part 13 in the first member 30. In theelectron tube according to the present embodiment, one ends of thepenetrating member 3 and the power supply part 13 may project from thesurface 30 a of the first member 30.

Although the embodiments have been described above, one aspect of thepresent invention is not limited to the above embodiments.

The electron tube to be manufactured may have the followingconfiguration. For example, similarly to an electron tube 1B shown inFIG. 14A, a penetrating member 3B may be provided in place of thepenetrating member 3 (see FIG. 1). The penetrating member 3B does nothave the enlarged part 3 b ₁ and the holding part 3 b ₂ (see FIG. 1).The penetrating member 3B is continuously inclined such that a diameterof the penetrating member 3B decreases toward the distal end side overthe entire extending direction thereof, and passes through the main bodypart 5 of the housing 2 and projects into the internal space R from thebottom surface 9 a of the recess 9. In addition, a distal end face ofthe penetrating member 3B is made to function as the cathode K withoutseparately providing the photoelectron emitting part 14. That is, sincethe cathode K (electrode) is integrally formed with the penetratingmember 3B, the number of manufacturing steps is reduced and the electrontube 1 can be manufactured more easily. In addition, since there is nojoint part, an electrode with excellent earthquake resistance can beobtained.

In addition to being applicable as an ultraviolet detector as in theabove embodiment, the electron tube to be manufactured can be applied asa light source or the like as a light emitting element (energygenerating element). For example, an electron tube 1C shown in FIG. 14Bhas a structure as a discharge lamp. In the electron tube 1C, a pair ofpenetrating members 3 are arranged in one internal space R, metal parts53 serving as the cathode K and the anode A are attached to respectivedistal end sides of the penetrating members 3, and discharging betweenboth electrodes enables operation as a lamp. The electron tube 1Cincludes a probe pin 51 and a sparker pin 52 that pass through the mainbody part 5 and project into the internal space R, for discharge. Themetal part 53, the probe pin 51, and the sparker pin 52 serve aselectrodes for emission of light.

Further, for example, an electron tube 1E shown in FIG. 15A has astructure as a discharge lamp. In the electron tube 1E, a pair ofpenetrating members 3 are arranged in one internal space R, metal parts53 serving as the cathode K and the anode A are attached to respectivedistal end sides of the penetrating members 3, and discharging betweenboth electrodes enables operation as a lamp. The electron tube 1Eincludes a probe pin 51 passing through the main body part 5 andprojecting into the internal space R for discharge, a sparker electrode(not shown) provided on the inner surface of the lid part 6 andelectrically connected to the power supply part 13. The metal part 53,the probe pin 51, and the sparker electrode serve as electrodes foremission of light.

Further, for example, an electron tube 1F shown in FIG. 15B has astructure as a discharge lamp. In the electron tube 1F, a pair ofpenetrating members 3, metal parts 54 serving as the cathode K and theanode A are disposed in one internal space R, and discharging betweenboth electrodes enables operation as a lamp. In the present embodiment,the metal parts 54 alone serve as electrodes for emission of light.

Further, for example, an electron tube 1G shown in FIG. 15C has anelectron source structure. In the electron tube 1G, in a state where atarget material 56 is arranged facing to an emitter 14 e fixed to thedistal end side of the penetrating member 3, a predetermined voltage isapplied between the target material 56 and the emitter 14 e to form suchan electric field that leads electrons emitted from the emitter 14 e tothe target material 56. For example, in a case where the target material56 is a phosphor, causing collision of electrons allows fluorescentlight emission to be generated. Further, changing the target material 56to various materials enables X-rays to be generated and electron beamsto be transmitted. During operation, the internal space R is evacuated.The emitter 14 e serves as an electrode for generation of energy.

In the above embodiment, the sealing material 16 is provided on thefirst base film 15 of the first member 30 (see FIG. 7C). Alternatively,the sealing material 16 may be provided on the second base film 17 ofthe second member 40. Further, in a case where frit glass is used forthe sealing material 16, the first base film 15 and the second base film17 may be omitted.

In the above embodiment, the power supply part 13 is provided on theperiphery of the recess 9 in the main body part 5, but the position ofthe power supply part 13 is not limited. It suffices that the powersupply part 13 is provided on the main body part 5 so as to pass throughthe surface 30 b from the surface 30 a of the first member 30 (passthrough inside the first plate-shaped part 7 and the side wall part 8).For example, a raised part may be provided at one corner among fourcorners of the recess 9 such that the side surface of the recess 9bulges inward, and the power supply part 13 may be provided so as topass through the raised part. In the above embodiment, the insulatingpart 12 is formed integrally with the main body part 5, but theinsulating part 12 may be formed separately from the main body part 5.

In the above embodiment, a part of the side surface of the internalspace projecting part 11 is covered with the insulating part 12.However, it suffices that at least a part of the side surface of theinternal space projecting part 11 is covered with the insulating part12. In the above embodiment, all of the enlarged part 3 b ₁ is coveredwith the insulating part 12, but it suffices that at least a part of theenlarged part 3 b ₁ is covered with the insulating part 12. Further, thepenetrating member 3 has the cylindrical holding part 3 b ₂ at distalend thereof. However, the penetrating member 3 may be provided with acontinuous inclined surface from the enlarged part 3 b ₁ to the distalend without having a cylindrical part. In addition, the electron tube 1has one recess 9 alone, but single electron tube may have a plurality ofrecesses 9. In this case, it is also possible to use a single electrontube in a state of not being divided. In this case, the internal spacesR in the plurality of recesses 9 may be independent of each other or maybe in communication with each other. In this case, an electron tubehaving a desired area can be easily obtained. In the above embodiments,the materials, shapes, and dimensions of the individual configurationsare not limited to the above-described materials, shapes, anddimensions, and various materials, shapes, and dimensions can beadopted.

According to one aspect of the present invention, it is possible toprovide a manufacturing method of an electron tube that can easilymanufacture an internal structure of the electron tube.

What is claimed is:
 1. A manufacturing method of an electron tube, themanufacturing method comprising: a first step of preparing a firstmember made of an insulating material and a jig provided with aprotrusion, the protrusion being juxtaposed, narrowing toward a distalend side, and removably holding a conductive member, and heating atleast one of the first member and the jig to a temperature at which thefirst member can melt and deform; after the first step, a second step ofbringing the jig into contact with the first member to allow a pluralityof the protrusions to be embedded in the first member in a state wherethe first member and the plurality of the protrusions are facing eachother, removing the jig, and forming an intermediate body, theintermediate body including the first member in which a plurality ofrecesses expanding toward an opening side are formed corresponding tothe plurality of the protrusions, and including a plurality of theconductive members passing through the first member and projecting intothe recesses; and after the second step, a third step of preparing asecond member, hermetically joining the second member to theintermediate body by closing openings of the plurality of recesses toform a plurality of internal spaces where electron is emitted, andforming a joined body.
 2. The manufacturing method of an electron tubeaccording to claim 1, further comprising, after the third step, a fourthstep of cutting the joined body into a plurality of electron tubes tohave at least one of the internal spaces.
 3. The manufacturing method ofan electron tube according to claim 1, wherein a side surface of theprotrusion of the jig is continuously inclined to allow the protrusionto narrow toward a distal end side.
 4. The manufacturing method of anelectron tube according to claim 1, wherein the protrusion of the jighas a holding recess configured to hold, in a state where one end sideof the conductive member projects from the protrusion, another end sideof the conductive member; and a gap is formed at least in a part betweenanother end side of the conductive member held in the holding recess anda side surface of the holding recess.
 5. The manufacturing method of anelectron tube according to claim 4, wherein another end side of theconductive member held in the holding recess has an enlarged partexpanding toward the another end side; and a gap is formed in at least apart between the enlarged part and a side surface of the holding recess.6. The manufacturing method of an electron tube according to claim 5,wherein a side surface of the enlarged part is continuously inclined toallow the conductive member to expand toward the another end side of theconductive member.
 7. The manufacturing method of an electron tubeaccording to claim 1, wherein an area around the protrusion of the jigremovably holds a power supply member; in the second step, the jig isbrought into contact with the first member to allow the power supplymember to be further embedded in the first member, to form theintermediate body further including the power supply member; and in thethird step, a counter electrode member is provided on the second memberto face the conductive member projecting into each of the recesses, andthe counter electrode member is electrically connected to the powersupply member.
 8. The manufacturing method of an electron tube accordingto claim 1, wherein the second member is made of an insulating material.9. The manufacturing method of an electron tube according to claim 1,wherein at least one of a recess, a protrusion, or a rough surface partis formed on at least a part of a surface constituting the protrusion ofthe jig.
 10. The manufacturing method of an electron tube according toclaim 1, further comprising, after the first step, a step of pressing,with a pressing member, a side opposite to a side to be in contact withthe jig in the first member, wherein at least one of a recess, aprotrusion, or a rough surface part is formed in a contact region of thepressing member with the first member.
 11. The manufacturing method ofan electron tube according to claim 1, wherein, in the second step, theconductive member is embedded in the first member while exposing one endof the conductive member from the first member to allow the conductivemember to pass through the first member in the intermediate body, or thefirst member is polished until one end of the conductive member isexposed from the first member.